Actuated Scratchers for a Tracked Vehicle

ABSTRACT

A system and method for deploying scratchers for a tracked vehicle, such as a snowmobile, are described. The scratchers can be deployed in response to the engine temperature of the tracked vehicle exceeding a predetermined threshold. Alternatively, the scratchers can be deployed via actuation of a switch by an operator.

This application is a continuation of U.S. application Ser. No.15/811,945, filed Nov. 14, 2017, which claims benefit of U.S.Provisional Application No. 62/421,577, filed on Nov. 14, 2016 and whichapplication is incorporated herein by reference. A claim of priority ismade.

BACKGROUND

During operation, components of a snowmobile, such as the track andslide rails, may be cooled and lubricated by sprays of loose snow thatare generated during the normal operation of the snowmobile on loosesnow. Additionally, devices have been developed to scratch a surface ofthe ice or snow to generate a spray of ice or snow when a snowmobileoperates in order to provide a desired cooling and lubrication. Thesedevices are known by many different names such as snow tillers, spraygenerating devices, ice or snow scratchers, and snow lubricationdevices.

SUMMARY

Embodiments relate to a snowmobile comprising a main frame and a tunnelcoupled to the main frame, and a skid frame assembly coupled to thetunnel. The skid frame assembly includes a rear suspension, at least oneskid rail coupled to the rear suspension, and at least one actuatorhaving a scratcher coupled thereto. The actuator has a deployedconfiguration and an undeployed configuration.

Embodiments also relate to a method for automatically deployingscratchers coupled to a snowmobile, the method comprising the steps ofproviding an engine, providing at least one scratcher, providing atemperature sensor, determining, with the temperature sensor, thetemperature of the engine, and deploying the at least one scratcher whenthe temperature of the engine is greater than or equal to apredetermined threshold.

Embodiments relate to a method for automatically deploying at least onescratcher coupled to a snowmobile, the method comprising the steps ofproviding an engine having a cooling system, providing at least onescratcher, providing a temperature sensor, determining, with thetemperature sensor, the temperature of the coolant within the coolantsystem, and deploying the at least one scratcher when the temperature ofthe coolant is greater than or equal to a predetermined threshold.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in difference views. The drawingsillustrate generally, by way of example, but not by way of limitation,various embodiments discussed in the present document.

FIG. 1 shows a projection view of an embodiment of a snowmobile.

FIG. 2 shows a side view of an embodiment of a snowmobile.

FIG. 3 shows a projection view of an embodiment of a snowmobile.

FIG. 4 shows a projection view of an embodiment of a snowmobile.

FIG. 5 shows a projection view of an embodiment of a portion of asnowmobile.

FIG. 6 shows a projection view of the portion of the snowmobile of FIG.5.

FIGS. 7, 9, and 10 show side views of an embodiment of a scratcherassembly.

FIG. 8 shows a front view of the scratcher assembly of FIG. 7.

FIG. 11 shows an example of a logic flow chart.

FIG. 12 shows an embodiment of a selector switch.

FIG. 13 shows another example of a logic flow chart.

FIG. 14 shows an embodiment of a selector switch.

FIGS. 15 and 16 show examples of logic flow charts.

FIG. 17 shows an example of an electrical circuit.

DETAILED DESCRIPTION

As shown in FIG. 1, a tracked vehicle 1, such as a snowmobile, comprisesa frame 12 (FIG. 3), one or more skis 14 attached to the frame via afront suspension 16, a track 18, at least one seat 20, handlebars 22, anengine compartment 23 (FIG. 3), and an engine 24 (FIG. 3). Additionally,in at least some embodiments, the seat 20 is a straddle seat. Thetracked vehicle also includes, in at least some embodiments, a skidframe assembly 26 comprising a rear suspension 28 (FIG. 2). In someembodiments, the rear suspension 28 is coupled to the frame 12 of thetracked vehicle, for example, via a tunnel 30.

As shown in FIGS. 2-5, in at least some embodiments, the skid frameassembly 26 includes one or more skid rails 27. As shown in FIG. 3, theskid rail(s) 27 include a wear strip 6 adjacent to a lower surface ofthe skid rail(s) 27. In at least some examples, the one or more skidrails 27 are formed from an aluminum material, however, a polymericmaterial, or any other suitable material, can be employed. Combinationsof materials, alloys, metals, plastics, etc., can also be used. In someexamples, the skid frame assembly 26, or at least a portion thereof, isformed from a hollow member which can be located along a longitudinalcenterline of the tracked vehicle 1, for example as shown in U.S. Pat.No. 9,321,509, the contents of which are herein incorporated byreference in their entirety. Further, in some embodiments, the skidframe assembly 26, or at least a portion thereof, includes multiplehollow members which can be laterally offset from one another and whichgenerally extend in the longitudinal direction of the tracked vehicle 1.

With further regard to FIGS. 3 and 4, in some embodiments, the trackedvehicle 1 has one or more scratchers 32. The scratchers 32 can bedeployed to throw snow and/or ice into the skid frame assembly 26 toprovide lubrication for the track 18 and skid frame assembly 26 and,further, to cool the engine 24, for example via a heat exchanger 52,which can be located beneath a portion of the tunnel 30 or as a portionof the tunnel 30. In at least some embodiments, the heat exchanger 52includes coolant passages (not shown) through which coolant flows tocool the engine 24. In some embodiments, the one or more scratchers 32are formed from a spring-steel material, though other materials can alsobe used. In some embodiments, the scratchers 32 are deployed in order toprevent overheating of the engine, as discussed in greater detail below.

With regard to FIG. 5, in at least some embodiments, the one or morescratchers 32 are coupled to an actuator 34. The actuator 34, in turn,is mounted to the skid frame assembly 26, or other suitable portion ofthe tracked vehicle 1, for example via a fastener such as a bolt, rivet,strap, etc. In at least some embodiments the actuator(s) 34 iscontrolled electromechanically, however the actuator can be purelymechanical (e.g., cable actuated), or it can be hydraulic, pneumatic, orany suitable combination. As will be appreciated, other actuation modescan also be employed. In some embodiments, the actuator(s) 34 comprisesa rotary actuator; in some embodiments, a linear actuator is employed;some embodiments utilize a direct current motor, such as astepper-motor; some embodiments employ a solenoid. Again, other modescan also be utilized.

Further, the one or more actuators 34 can mounted in any suitablelocation. Where the one or more actuators 34 are mounted to one or moreof the skid rails 27, they can be mounted thereto in any suitablelocation, for example, ahead of a shock attachment location, behind ashock attachment location, etc. As will be appreciated, other locationsmay also be suitable. Referring to FIG. 6, in some embodiments, the skidframe assembly 26 includes a plurality of scratcher assemblies 54. In atleast some embodiments, the skid frame assembly 26 includes twoscratcher assemblies 54, each scratcher assembly including an actuator34 and a at least one scratcher 32. In some embodiments, a scratcherassembly 54 is coupled to an outer side of the skid rail 27, as shown inFIG. 6, for example. As shown in FIGS. 9 and 10, the actuator 34 has afirst configuration 36 and a second configuration 38. In the firstconfiguration 36 the scratcher(s) 32 is retracted; in the secondconfiguration 38 the scratcher is deployed. Upon deployment, at least aportion of the scratcher(s) 32 contacts the ground. In at least someembodiments, the scratcher(s) 32 make contact with snow or ice coveringthe ground. In some embodiments, the scratcher(s) 32 includes one ormore bent portions 40 and one or more straight portions 42.

Referring to FIG. 7, arrow 56 illustrates rotation of the scratcher 32about pivot axis 58 (FIG. 8), in order to deploy or retract thescratcher 32. In FIGS. 7 and 8, a rotary-style actuator is illustrated,however, any suitable of actuator can be employed.

Referring to FIG. 11, an embodiment of a flow chart 50 for deploying orretracting the one or more actuators 34 is shown. In some embodiments,the tracked vehicle 1 includes a selector switch 44 (FIG. 1), which canbe located on the handlebars 22, or any other suitable location (e.g.,electronic display with touch-pad, body panel, etc.). The selectorswitch 44 can have one or more selectable configurations. As illustratedin FIG. 12, the selector switch 44 can be manually operable by the riderto select between the deploy configuration 60 and retract configuration62. In some embodiments, the selector switch 44 is 2-position toggleswitch, however a rotary, momentary, or any other suitable switch can beutilized.

Returning to FIG. 11, in some embodiments, the tracked vehicle 1includes logic for retracting or deploying the one or more scratchers 32via the one or more actuators 34. In some embodiments, for example, thelogic will not deploy the scratchers 32 if the tracked vehicle 1 is inreverse. As will be appreciated, operating the tracked vehicle 1 inreverse with the scratchers 32 deployed could cause damage to thescratchers 32. The logic can be implemented via an ECU (engine controlunit), analog circuit, dedicated processor, or in any other suitableway.

With regard to FIG. 14, in some embodiments, the selector switch 44 is a3-position switch. In some embodiments, the selector switch 44 is arotary switch, for example as shown in FIG. 14. By way of example, andas shown in FIG. 14, the selector switch includes a retractconfiguration 62 (illustrated via “R” in FIG. 14), deploy configuration60 (illustrated via “D”), and an auto configuration 64 (illustrated via“A”). The selector switch 44 shown in FIG. 14 can be rotated to any ofthe three configurations—R, D, A, respectively.

Referring to FIG. 13, an example of control logic governing theoperation of the switch of FIG. 14 is illustrated. When placed in theretract configuration, corresponding to reference numeral 62 in FIG. 14,the actuator 34 will retract the scratcher 32 (or maintain thescratcher(s) 32 in a retracted configuration if the scratcher is alreadyarranged in the retracted configuration). When placed in the deployconfiguration, corresponding to reference numeral 60 in FIG. 14, theactuator 34 will deploy the scratcher 32 if the control logic determinesthat the vehicle is not placed in reverse. Finally, where the switch 44is placed in the auto configuration, corresponding to reference numeral64 in FIG. 14, the actuator 34 will retract and deploy the scratcher 32automatically. In some embodiments, the actuator 34 will deploy(maintain deployment) the scratcher 32 when two conditions aresatisfied: (1) the tracked vehicle 1 is not in reverse and (2) thetemperature sensor determines that the temperature has reached apredetermined threshold value. When the temperature falls below thethreshold value, the scratcher(s) 32 are automatically retracted(maintained in a retracted configuration). Further, when the trackedvehicle 1 is placed in reverse the scratcher(s) 32 are automaticallyretracted. In some embodiments, the temperature sensor samples thecoolant temperature of the coolant flowing through the engine 24. Insome embodiments, the temperature sensor measures the temperature of theengine 24 directly, for example cylinder head temperature. In someembodiments, the temperature sensor measures the ambient air temperatein the engine compartment 23.

Turning to FIG. 15, in some embodiments, the tracked vehicle 1 doesn'thave a selector switch 44 and, instead, the actuator(s) 34 automaticallydeploy the scratcher(s) 32 when: (1) the tracked vehicle 1 is not inreverse and (2) the temperature sensor determines that the temperaturehas reached a predetermined threshold value. In some embodiments,however, the selector 44 can simply be an ON/OFF switch. In an “OFF”configuration, the actuator(s) 34 do not deploy the scratcher(s) 32. Inthe “ON” configuration, however, the actuator(s) deploy the scratcher(s)32 when: (1) the tracked vehicle 1 is not in reverse and (2) thetemperature sensor determines that the temperature has reached apredetermined threshold value. When the temperature falls below thethreshold value, the scratcher(s) 32 are automatically retracted.Further, when the tracked vehicle 1 is placed in reverse thescratcher(s) 32 are automatically retracted.

With regard to FIG. 16, an embodiment of control logic is shown. In thisinstance, the actuator(s) 34 will retract (or maintain in a retractedconfiguration) when the temperature is below a predetermined threshold.Further, the actuator(s) 34 will retract (or maintain in a retractedconfiguration) when the tracked vehicle 1 is placed in reverse.

In some embodiments, the scratcher(s) 32 will remain in firstconfiguration 36 regardless of sensor measurements (e.g., temperaturesensor measurement), vehicle speed, forward/reverse configuration, orany other suitable inputs which might otherwise activate the actuator(s)34. In some embodiments, the actuator(s) 34 will retract or deploy inresponse to the tracked vehicle 1 traveling at a predetermined speed.For example, the actuator(s) 34 can retract the scratcher(s) 32 above athreshold speed.

In some embodiments, the temperature sensor will continuously evaluatethe temperature of the engine or engine's cooling system, or otherdesired condition designed to activate the actuator(s) 34. In someembodiments, an ECU (electronic control unit) 46 automatically controlsthe actuator(s) 34.

With further regard to FIG. 17, an example of an electrical circuit 45is shown. In some embodiments, the ECU will take inputs from thetemperature sensor 4 and a reverse input switch 49. When the ECUdetermines that the temperature exceeds a predetermined thresholdtemperature, the ECU will send a “command down” signal to the actuator34 to deploy the scratcher(s) 32, unless the reverse input switch 49indicates that the tracked vehicle 1 is in reverse. Further, when theECU determines that the temperature drops below a predeterminedthreshold temperature, the ECU will send a “command up” signal to theactuator 34 to retract the scratcher(s) 32. It will be appreciated that,in some embodiments, the ECU will monitor the configuration of theactuator 34 (deployed or retracted) and no signal will be sent to theactuator 34 unless desired. For example, if the scratcher(s) 32 areretracted and the temperature sensor 4 determines that the enginetemperature has exceeded the predetermine threshold temperature, the ECUwill not send a “command down” signal to deploy the scratcher(s) 32 ifthe tracked vehicle 1 is in reverse.

In some embodiments, the ECU will monitor the configuration of theactuator(s) on a period basis, for example once every 500 milliseconds,or other appropriate time interval.

In some embodiments, the predetermined temperature threshold to deploythe scratcher(s) 32 is different than the predetermined temperature toretract the scratcher(s). For example, in some embodiments, thepredetermined threshold to retract the scratcher(s) is less than thepredetermined temperature used to deploy the scratcher(s) 32. In someembodiments, this is desirable to reduce the likelihood that thescratcher(s) 32 will be repeatedly deployed and retracted. Additionally,in some embodiments, when the measured temperature decreases by apredetermined amount, the scratcher(s) 32 will retract into firstconfiguration 36. Further still, the ECU, via temperature sensor 4, candetermine the rate of change in temperature. In this way, the ECU cansend signals to deploy or retract the scratcher(s) 32, at least in part,based on a control system having greater inputs. For example, the ECUcan rely on a PI, PD, or PID (proportional—integral—derivative)algorithm or controller.

While the above detailed description has shown, described, and pointedout novel features of a tracked vehicle as applied to variousembodiments, it will be understood that various omissions,substitutions, and changes in the form and details of the device orprocess illustrated may be made by those skilled in the art withoutdeparting from the spirit and scope of the disclosure. The applicationis, therefore, intended to cover any variations, uses, or adaptations ofusing these general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains.

What is claimed is:
 1. A snowmobile comprising: a tunnel; a skid frameassembly coupled to the tunnel, the skid frame assembly comprising: arear suspension; at least one skid rail coupled to the rear suspension;and at least one actuator having a scratcher coupled thereto, whereinthe actuator has a deployed configuration and an undeployedconfiguration; wherein the at least one actuator is controlled by anengine control unit.
 2. The snowmobile of claim 1, wherein the scratchercomprises at least a straight portion and a bent portion.
 3. Thesnowmobile of claim 1, further comprising a cooling system to cool theengine.
 4. The snowmobile of claim 3, further comprising a temperaturesensor to determine the temperature of the coolant.
 5. The snowmobile ofclaim 3, wherein, when the coolant is above a predetermined temperature,the actuator deploys the at least one scratcher to the deployedconfiguration.
 6. The snowmobile of claim 5, wherein, when the coolantis below a predetermined temperature, the actuator retracts the at leastone scratcher to the undeployed configuration.
 7. The snowmobile ofclaim 1, wherein the actuator comprises a direct current motor.
 8. Thesnowmobile of claim 1, wherein the scratcher is formed fromspring-steel.
 9. The snowmobile of claim 1, wherein the at least oneactuator is attached to the skid frame.
 10. The snowmobile of claim 10,wherein the at least one actuator is attached to the skid rail.
 11. Thesnowmobile of claim 1, further comprising a selector switch.
 12. Thesnowmobile of claim 11, wherein the selector switch comprises a3-position selector switch.
 13. The snowmobile of claim 12, wherein the3-position selector switch comprises a retract configuration, a deployconfiguration, and an auto configuration.
 14. A method for automaticallydeploying scratchers coupled to a snowmobile, the method comprising thesteps of: providing an engine; providing at least one scratcher, thescratcher capable of being in a deployed or undeployed configuration;and determining whether the snowmobile is in forward, neutral, orreverse; maintaining the at least one scratcher in an undeployedconfiguration if determined to be in reverse.
 15. The method of claim14, further providing a temperature sensor.
 16. The method of claim 15,further comprising determining, with the temperature sensor, thetemperature of the engine; and deploying the at least one scratcher whenthe temperature of the engine is greater than or equal to apredetermined threshold
 17. A snowmobile comprising: a tunnel; a skidframe assembly coupled to the tunnel, the skid frame assemblycomprising: a rear suspension; at least one skid rail coupled to therear suspension; at least one actuator having a scratcher coupledthereto, wherein the actuator has a deployed configuration and anundeployed configuration; and at least one selector, in communicationwith the at least one actuator.
 18. The snowmobile of claim 17, whereinthe at least one selector is in electronic communication with the atleast one actuator.
 19. The snowmobile of claim 17, wherein the at leastone selector is in mechanical communication with the at least oneactuator.
 20. The snowmobile of claim 17, wherein the at least oneactuator is attached to the skid rail.